GEOGRAPHICAL ADVANTAGES. 
313 
Grallae is equal. It is here then that our county 
excels in the ornithological department, at least 
such is the fair conclusion by comparison with 
the products of this other county possessing a 
tolerably extensive ornithological Fauna, and con¬ 
sidering the respective histories of the species in 
which Oxfordshire is deficient our advantage can¬ 
not be set down to maritime position. On the 
contrary, I believe the true reasons may be stated 
as follows:—ls£, There are certain European birds 
whose chief situation is in France, Italy, Holland, 
and other adjoining countries, but whose range ex¬ 
tends to the southern portions of Great Britain, just 
as the range of others is found to extend from Europe 
to the northern shores of Africa. There are other 
species also whose principal station is in Africa, and 
which migrate yearly into Europe, reaching in small 
numbers the British Isles ; and since the number of 
animals generally diminishes northward, the pro¬ 
portion of birds resident in, or migrating to the 
southern shores of Britain will be greater than that 
of the northern parts. 2 dly, Montagu states as his 
opinion, that in the autumnal migration of the long, 
soft-billed Waders (and I suppose other kinds also) 
from their northern haunts to the southern portions 
of Europe, they experience in their transit across 
the north sea, equinoctial gales which gradually 
drive them to the southern parts of England, so that 
hence we are more likely than northern counties to 
have rarities conferred on us. 3 dly, This county 
contains almost every kind of retreat for the various 
sorts of birds : it is mountainous, well-wooded, and 
well watered. 4 thly, In the retreat of those birds 
which visit this country from southern latitudes 
to their winter residences, the southern coasts of 
England offer them a resting place previous to their 
departure, so that here we see a larger number both 
of individuals and of species than the generality of 
